To address the problems like static nature, unfairness and complexity in Selfish Misbehavior (SM) processing mechanism of Medium Access Control (MAC) protocol of Mobile Ad Hoc NETwork (MANET), an optimization algorithm for SM was proposed. By using optimization theory and feedback theory, the Optimal Access Probability (OAP) was conducted through the utilization of historical samples, realizing the dynamic change of parameters to improve static nature. Then, all nodes in the network were set to use the OAP at the given period, thus the fairness index of the network was promoted. Finally, linear iteration mechanism was adopted to avoid the increase of complexity. On basis of the above, stability and effectiveness of the proposed algorithm were proved theoretically by Lyapunov algorithm and global stable point. Experimental results show that, by the proposed algorithm, the number of SM decreases by 30%-50%, the end-to-end delay brings down 8-10 ms, the throughput increases about 0.5 Mb/s, the fairness index raises by 0.05, while the control overhead remains unchanged, all of which indicates that the performance of the SM processing mechanism has been improved.

A novel optimized model of distributed multi-hop Cognitive Medium Access Control (C-MAC) protocol with a single transceiver was proposed to handle two restrictions in MAC protocol of Mobile Ad Hoc NETwork (MANET). One is the restriction of multiple transceivers and payload imbalance in different channels, and the other one is the restriction of multi-hop and control overhead. Firstly, channel sensing and data transmission of the new C-MAC protocol were realized in ATIM (Announcement Traffic Indication Message) window and DATA window respectively based on Power Saving Mode (PSM), which made them separated in time domain. Secondly, power value was nonuniform quantized and Gray encoded to decrease float overhead caused by node mobility. Then, a distributed cooperation mechanism was raised for multi-hop networking, based on which channel switching rule was redefined to guarantee that channels would be used fairly and balanced. Last, metrics as Channel Vacate Time (CVT), Channel Opening Time (COT), throughput and channel payload time were considered by simulation. Results show that, the novel protocol could execute independently without several transceivers, the difference values of CVT, COT and payload time among different channels reduce by 13 ms, 20 ms and 100 s respectively, and corresponding throughput rises about 1.5%, all of which realize the optimization of protocol performance in transceiver restriction, payload balance, throughput and overhead control.

Aiming at the problems of single hop and static nature in theoretical analysis of Media Access Control (MAC) protocol, a multi-hop analysis model for Mobile Ad Hoc NETwork (MANET) was proposed, and a real-time estimation algorithm for neighbor node was designed. Firstly, a common multi-hop throughput analysis model was established through definition of distance parameter, which equaled to the Ratio of Euclidean distance and Real statistical distance (ERR), based on 2-D discrete time Markov Chain (DTMC) model, with nodes distributed in a Poisson Network (PN). Secondly, one of the reasons resulting in deviation between theory and simulation, dynamic nature of neighbor nodes, was analyzed qualitatively, that was, ERR didn't take mobility into consideration. Thirdly, a real-time number estimation methodology of neighbor nodes in PN with Random Walk (RW) mobility model was presented based on Kalman filter algorithm through redefinition of state update rule as well as measurement rule. Finally, the performance of the multi-hop throughput analysis model was compared and analyzed. The experimental results show that, although the delay of 0.13 s is introduced, the accuracy is improved by 8% in terms of throughput, Therefore, both extension of multi-hop communication and consideration of mobility are realized in the model.

Concerning the low throughput and fairness of multi-rate Medium Access Control (MAC) protocol in Mobile Ad Hoc Network (MANET), saturation throughput expressions of nodes with different rates were deduced, and the key factor to restrict performance of MAC protocol was quantitatively analyzed, which is unfairness of channel occupancy time between Slow rate Nodes (SN) and Fast rate Nodes (FN). Secondly, focusing on maximizing time fairness among different rates of nodes, two optimal methods of Contention Window (CW) and packet size were presented without affecting the throughput of SN but maximizing the throughput of FN, which makes the saturation throughput of MANET optimal. Experimental results show that, to maximize Jain fairness index when packet rates of two types of nodes are set to 1 Mb/s and 11 Mb/s, optimal values of CW in simulation and analysis are 320 and 350, respectively; similarly, values of packet size are 64 B and 60 B. Moreover, although saturation throughput value of SN basically remains unchanged, the total throughput of analysis is still 0.2-0.5 Mb/s higher than that of simulation. Therefore, throughput and fairness are both improved.

Since Mobile Ad Hoc NETwork (MANET) has imbalance of high throughput but low fairness, a novel Medium Access Control (MAC) protocol named MAC-FT was proposed. Firstly, two expressions were deduced and focus on relationship of optimal throughput and nodes' number, and relationship of idle slot probability and nodes' number. On the basis of this, idle slot probability model was developed, whose feasibility and stability were proved based on Lyapunov drift. Secondly, idle slot probability computation was implemented through Auto-Regressive and Moving Average (ARMA) model filter scheme and its dynamics was controlled by Proportional Integral Controller (PIC) model. Finally, performance of MAC-FT was analyzed synthetically. Results show that, fairness index and throughput reached to 0.98 and 6.15 Mb/s respectively, which were similar to optimal value 1 and 5.85 Mb/s. Therefore, performance of MAC-FT is better than Asymptotically Optimal Backoff (AOB), Idle Sense (IS), Distribution Coordination Function (DCF), and Gentle DCF (GDCF), and it improves balance of throughput and fairness.

To deal with the performance bottleneck of operating the Device Independent Bitmap (DIB) in Wine, a method of client software rendering was brought forward. This method firstly analyzed GDI API for operating DIB, and then confirmed the load point of client software rendering, subsequently designed a list for linking different device context and their corresponding GDI API, at last realized the client software rendering of GDI API. The performance test shows that compared with the Wine without optimization, the average graphic performance of the Wine with the optimization of client software rendering enhances at least 10 times when it operates DIB, and is close to the performance of the local Windows XP, which effectively avoids the performance bottleneck of operating DIB.